Trimming mechanism for sewing machines



A. H. DE VOE. TRIMMING MECHANISM FOR SEWING MACHINES.

m APPLICATION FILED MAR- 3, 1920. 1,433, (Q50 Pamm/ed (M. 311, 11922.

3 SHEETS-SHEE1 l.

/ IIIII WI'II'NIES s: NVENTOR W 1 ATTORNEY A. H. DE VOE. TRIMMINGMECHANISM FOR SEWING MACHINES.

APPLICATION FILED MAR. 3, 1920. A Lw fiiwn Emma 0%31 1922 3 SHEETSSHEET2- III I IILI-N WWNEESS t5! INVENTOR A. H. DE VOE. v TRIMMING MECHANISMFOR SEWING MACHINES.

I APPLICATION FILED MAR- 3, I920. L4I3$fi5 Patented Oct 311, 1922' 3SHEETS-SHEET 3.

2 INVENTOR ,JMQ g MJW 4 BY z" 19 I ATTORNEY Patented Get. 31, 1%22.

UNHTED @FFHQE.

ALBERT H. DE VOE, OF WESTFIELD, NIIEW JERSEY, ASSIGNOR TO THE SINGERMANU- FACTUPJIINTG COMPANY, OF ELIZABETH, NEW JERSEY, A CORPORATION OFNEW JERSEY.

TBIMMING MECHANISM FOR. SEWING MACHINES.

Application filed March 3; 1920. Serial No. 363,044.

To all whom it may concern:

Be it known that T, ALBERT H. DE Von, a citizen of the United States,residing at Westfield, in the county of Union and State of New Jersey,have invented certain new and useful Improvements in Trimming Mechanismsfor Sewing Machines, of which the following is a specification,reference being had therein to the accompanying drawings.

This invention relates to trimming mechanisms for sewing machines andhas for an object to provide such a mechanism capable of operating at ahigh rate of speed with a minimum of friction, noise and vibration.

A. further object is to provide a trimming mechanism capable of beingthrown into and out of action during the running of the machine andwhich is devoid of latches, locks &c.

A still further object is to provide a trimming mechanism ofthe abovecharacter adjustable relative to the line of scam formation Whereb thefabric may be trimmed at various distances from the seam.

The objects of the invention are attained in the present mechanism whichpreferably comprises an upper trimmer-blade carried by the lower end ofa vertically reciprocating trimmer-bar guided in the machine head andwhich is actuated from and constantly connected with a rotarytrimmeractuating shaft carried by and extending lengthwise of themachine arm and driven from the main-shaft of the machine. The upper.trimmer-blade cooperates with a stationary trimmer or ledger-bladecarried by the throat plate of the machine and which is adjustabletransverse to the line of scam formation for varying the workingposition of the trimmer-blades with respect to the seam.

Operative movements of the trimmerblade may be effected or discontinuedby means of a hand-lever conveniently located adjacent the machine headand which determines the position of the fulcrum of a connection betweenthe cutter-bar and the trimmer-actuating shaft, the position of saidfulcrum determining the action or inaction of the trimmer as will laterbe explained.

The invention is illustrated in its preferred form in the accompanyingdrawings, in which Fig. 1 is a rear elevation partly in section of asewing machine embodying the present invention. Fig. 2 is an end viewpartly in section of the machine shown in Fig. 1. Fig. 3 is a detailside elevation of the trimming mechanism looking in a direction oppositeto that of Fig. 2. Fig. 4 is a sectional view taken on the line 4-4 ofFig. 2. Fig. 5 is a detail plan view of the throat-plate of the machineand the ledger-blade carried thereby showing in dotted lines the lateraladjustment of the throat-plate and ledgerblade, andFig. 6 is an enlargeddetail sectional view on the line 6-6 of Fig. 5 showing in full anddotted lines two operative positions of the trimmer-blades.

Referring more particularly to the drawings, the trimming mechanism isshown embodied in a sewing machine constructed with a base 1 formedintegral with the standard 2 which carries the overhanging arm 3terminating in the head 4:. The main-shaft 5 is supported in bearingscarried by the base 1 and is provided with a hand-wheel and pulley 6 anda crank 7 which actuates, through suitable -mechanism, the needle-bar 9carrying the needle 10. This needle-bar actuating mechanism comprises apitman 8 connected at its lower end to the crank 7 and at its upper endto an arm 8 fixed upon a needle-operating shaft 8 journaled in theoverhanging arm 3 and having fixed upon its forward end a. crankarm 8connected by a link 8 to a.collar on the needle-bar 9. Cooperating withthe needle 10 in the formation of stitches is the looper 11 actuatedfrom the main-shaft 5 through suitable mechanism 12.

.Feeding mechanism 13 is also actuated from the main-shaft 5 and acts tofeed the material between successive stitches.

Cooperating with the feeding mechanism is the resser-foot 14: securedupon the lower end of the spring-depressed presserbar 15 adapted to bemoved vertically in bearings 16 formed in the head 4. Slidably mountedwithin the head 4: is the trimmerbar 17 carrying at its lower end theflexible trimmer-blade 18 constructed with a pierc- I ing point 19 and acutting edge'20.

- motion 1 shaft 5 for operating mechanism supple- The trimmer-bar 17 isprovided with integrally formed lugs 21 and 21' apertured to embrace andslide upon the presser-bar 15 whereby the trimmer-bar is guided in itsreciprocating movements. The trimmerbar is prevented from turning aboutthe presser-bar 15 by the walls 22 of a cut 23 in the machine headthrough which the trimmer-bar passes. (See Fig. 4).

The main-shaft 5 isformed, adjacent the crank 7, with a second crank24'oblique to the axis of said main-shaft and about this crank is fitteda sleeve 25 connected by a pitman 26 to a like sleeve 27 surrounding alike crank 28 on the supplemental or trimmer-shaft 29 journaledsubstantially parparallel with the needle-operating shaft in bearings 30carried by the rear side of the arm 3, whereby through the elements 24,25, 26,27 and 28, the shaft 29 is given rotary in synchronism with themainmental to the stitch-forming mechanism such as, for example, thetrimmer mechanism described.

Upon the forward end of the shaft 29 is secured an eccentric element 31surrounded by a strap 32 having an arm 33, to which is pivoted at 34 oneend of a connecting element in the form of a trimmer actuating lever 35,the opposite end of which is pivoted at 36 to an car 37 projecting fromthe jug 21 on the trimmer-bar 17.

Thelever 35 is provided with a cam-slot 38 into which projects a roller39 carried by the upper end of an arm 40 fixed upon one end of a shortrock-shaft 41 journaled within the machine head and upon the oppositeend of which is secured a hand-lever 42 for manually adjusting theroller 39 in the slot 38 to render the trimming mechanism eithereffective or ineffective.

en the arm 40 is in the position shown in Figs. 2 and 3, the roller 39constitutes a fulcrum for the lever 35 by means of which the lever givesto the trimmer-bar. oppositely directed reciprocatory movements withrespect to the arm 33 actuated from the eccentric 31 but when, bymanipulation of the hand-lever 42, the arm 40 is moved tothe positionshown in dotted lines, Fig. 3, with its roller 39 in the ineffectiveportion 38" of. the slot 38 and adjacent the pivot 36, the roller 39acts upon the wall 38 of the cam-slot 38 causing the trimmer-bar to beraised and the trimmer-blade to be retracted from operative position andthe lever 35 then oscillates idly about the pivot 36, no movement beinggiven to the trimmer-barl A retaining spring 43, secured upon theoverhanging arm 3, acts upon the lug 44 on the hub of the hand-lever 42to maintain the arm 40 and roller 39 in either of the two positions justdescribed.

Cooperating with the flexible trimmerblade 18 is a trimmer orledger-blade 45 carried by the throat-plate 46 supported by standards 47and 47 rising from the base 1 and upon a projection 48 of thisthroatplate is pivotally secured a trimmer-guard 50'. A coil spring 51seated within a cavity in the throat-plate bears against the rearwardend of the trimmer-guard and acts to hold the forward end 50 against thetrimmer-blade 18, whereby the. trimmings are prevented from beingcarried beneath the throat-plate. The trimmer-guard being spring-pressedagainst the trimmer-blade yields therewith in its lateral adjustmentsnow to be described.

For the purpose of regulating the working position of the trimmer withrespect to the seam, the throat-plate 46 is pivoted near one end upon ascrew 52 threaded into an extension of the standard 47 and is at itsopposite end provided with spaced walls 53 and 53 upon which acts a cam54 fitted about the shank of a screw 55 passing through a. slot 56 inthe throat-plate 46 and threaded into the standard 47. By manuallyadjustin the cam 54 from the position shown in .full lines, Fig. 5, tothat shown in dotted lines, the cam acts upon the wall 53 and moves thethroat-plate and the ledger-blade carried thereby laterally of the lineof scam formation and changes the working position of the trimmer, itbeing understood that the trimmer-blade is thereby flexed out of itsnormal position and moves with the ledger-blade 45.

The piercing point of the trimmer-blade 18 is preferably bevelled at 19,which acts to deflect the trimmer-blade and prevent it from strikingupon the upper surface of the ledger blade when it is lowered to workingposition. I

Having thus set forth the nature of the invention, what I claim hereinis 1. In a sewing-machine constructed with a base, a standard and anoverhanging arm, in combination, a main-shaft journaled in said base, atrimmer-shaft carried by said overhanging arm and actuated by and insynchronism with said main-shaft, a trimming mechanism comprising astationary trimmer-blade, a movable trimmer-blade and a movabletrimmer-bar to which said movable trimmer-blade is secured and manuallycontrolled means connecting said trimmerbar with said trimmer-shaftwhereby said trimmer-shaft may be caused to actuate said trimmer-bar.

2. In a sewing machine provided with a mainshaft, a trimming mechanismcomprising a rotary trimmer-shaft actuated from said main-shaft, aneccentric element on said trimmer-shaft, a trimmer-bar, a trimmer-bladecarried thereby, a constantly moving connection between said trimmer-barand azar/ca said eccentric, and means whereby said connection may becaused to actuate said trimmer-bar.

3. In a sewing machine provided with a main-shaft, a trimmer-shaftactuated thereby, a trimmer-bar, a lever connected thereto and actuatedfrom said trimmer-shaft. a fulcrum for said lever, and means forshifting said fulcrum whereby the position of said fulcrum determinesthe action or inaction of said trimmer-bar.

4C. In a sewing machine provided with a main-shaft, a trimmer-shaftactuated thereby, a trimmer bar, a slotted trimmer-actuating leverpivoted thereto and actuated from said trimmer-shaft, a fulcrum for saidlever located, during the trimming operation, within said slot andintermediate the ends of said lever, and means for shifting saidfulcrurn to an inefiective point in said slot thereby discontinuing thetrimming opera- 5. A trimming mechanism for sewing machines comprising astationary trimmerblade, a movable trimmer-blade, a movable trimmer-barto which said movable blade is secured, a trimmer-actuating shaft, aslotted trimmer-actuating lever pivoted to 'said trimmer-bar andactuated by said trimmershaft, a rock shaft, an arm carried thereby, aroller carried by said arm and constituting a fulcrum for saidtrimmer-actuating lever, and means including a manually operable leverfixed to said rock-shaft for adjusting said fulcrum in said slot todetermine the action or inaction of said trimming mechanism.

6. In a sewingvmachine constructed with a base, a standard, anoverhanging arm and a head, in combination, a main-shaft journaledwithin said base, a trimming mechanism comprising a rotary trimmer-shaftactuated by said main-shaft, a stationary trimtrier-blade, a movabletrimmer-blade cooperating therewith, a movable trimmer-bar to which saidmovable trimmer-blade is secured, means for actuating said trimmer-barfrom said trimmer-shaft including a slotted lever, a fulcrum therefor,means for adjusting said fulcrum to determine the action or inaction ofsaid trimmer-bar, said lastmentioned means including a manually operablelever located adjacent the machine head, and means for maintaining saidlever in adjusted positions.

7. ltn a sewing machine constructed with a base, a standard, anoverhanging arm and a hollow head, in combination, a main-shaftjOhlltHfit-litld within said base, a trimming mechanism comprising arotary trimmer-actuating shaft carried by said overhanging arm in rearthereof and actuated by said main-shaft, a stationary trimmer-blade, amovable trimmer-blade cooperating therewith, a reciprocating trimmer-barsupported within said hollow head and to which the movable trimmer-bladeis secured and means for actuating said trimmer-bar including aneccentric carried by said trimmer-shaft and a lever connected to saidtrimmer-bar and operatively connected with said eccentric on saidtrimmer-shaft.

8. In a sewing machine provided with a main-shaft, a trimmer-shaftactuated thereby, a trimmer-bar, a trimmer-blade carried by saidtrimmer-bar, a lever connected to said trimmer-bar and actuated fromsaid trimmer-shaft, a movable fulcrum for said lever, and means forshifting said fulcrum to discontinue the movement of the trimmerbar andsimultaneously therewith to retract the trimmer-blade to an inoperativeposition.

9. In a. sewing machine constructed with a base, a standard, anoverhanging arm and a head, in combination, a throat-plate pivoted atone end to said base and provided at its opposite end with spaced walls,a normally stationary trimmer-blade carried by said throat-plate, atrimmer-bar slidingly mounted in said head, a flexible trimmer-bladecarried by said trimmer-bar and cooperating with said stationarytrimmer-blade, and a manually adjustable cam fitted within said spacedwalls and acting thereupon to turn said throat-plate about its pivot tochange the working position of said trimmer-blades.

10. In a sewin machine provided with a base, a late pivotally securedthereto, a trimmer-b ade secured to said plate, and means for adjustingsaid plate about its pivot to change the working position of saidtrimmer-blade.

11. In a sewing machine constructed with a base, a throat-platepivotally secured thereto and provided with spaced walls, atrimmer-blade carried by said throat-plate, and manually operable meansacting against said walls for turning said throat-plate about its ivotto change the working position of sand trimmer-blade.

12. In a sewing machine constructed with a base, a standard, anoverhanging arm and a head, in combination, a throat-plate pivoted tosaid base, a normally stationary trimmer-blade carried by saidthroat-plate, a trimmer-bar slidingly mounted in said head, a flexibletrimmer-blade carried by said trimmer-bar and cooperating with saidstationary trimmer-blade, a spring-pressed trimmer-guard pivotallyattached to said throat-plate and bearing against said flexibletrimmer-blade at the side opposite said stationary trimmer-blade, andmeans for turning said throat-plate about its pivot to change theworking position of said trimmer-blades and trimmer-guard.

13. In a sewing machine, in combination, a

' frame including a base, a standard, an overhanging arm and a head,stitch-forming mechanism incorporated in said frame and including areciprocating needle and a needle-operating shaft carried by saidoverhanging arm, a main-shaft journaled in said base, a drivingconnection between said main and needle-operating shafts, a rotarytrimmer-shaft carried by the overhanging arm in substantial parallelismwith the needle-operating shaft, means actuated by the main-shaft forrotating the trimmershaft, and a trimmer carried by the head andactuated by said trimmer-shaft, said trimmer including a blade operatingon the work adjacent the line of seam formation.

14. A sewing machine having, in combination, a frame including a base,astandard and an overhanging arm, a lower mainshaft journaled in saidbase and formed adjacent-the standard with a pair of cranks one of whichis inclined to the axis of said shaft, upper shafts carried insubstantial parallelism by the overhanging arm, a crank on one of saidupper shafts, an inclined crank on the other of-said upper shafts, asleeve on each of'said inclined cranks, a single pitman connectionbetween said sleeves, and an additional pitman connection between theother crank on the main-shaft and the crank on said one of the uppershafts, sewing mechanism including a needle actuated by one of saidupper shafts, and mechanism supplemental to the sewing mechanism andconnected. to be operated by the other of said upper shafts.

In testimony whereof, I have signed my name to this specification.

ALBERT H. DE VOE.

